1. Field of the Invention
The present invention relates to methods and devices for disintegrating calculi in the body, and in particular to a non-body invasive method and apparatus.
2. Description of the Prior Art
Disintegrating calculi, such as kidney stones, by means of ultrasonic shock waves is known, for example, from German OS No. 3122056. The existence of a boundary surface effect between body tissue and the stone structure is exploited. Reflection of the incident shock wave at the front or rear boundary surface of the calculus generates pressure or tensile forces which shortly result in the shattering of the calculus. In practice, coupling of the human body to a shock wave generator is undertaken by means of a water bath, which transmits the generated shock or pressure waves. This water bath also serves as a medium for removal of the ultrasonic energy which has passed by the stone region.
The use of such a water bath presents significant problems in patient support, as well as in monitoring the patient by means of a locating system, such as an X-ray system.